How to block Invalid numbers

[Oizocraze]

So I've been using freephoneline/fongo for quite a while and last year SipVicious called me a total of 3 times. So I thought it would never happened again, and I never anwsered either.
This year it's been calling me each day about 30 times per day and while I sleep it keeps calling me
and if I don't reject it, it never ends the call and continously rings without stopping, at all. This brings my computer to a stop and eventually reboot with a critical stop. I don't have a device yet from Freephoneline and/or Fongo. I use the Desktop interface. I use Windows XP because I'm a linux user and the program does not support nor wine or linux, so I just need the bare minimum of Windows and the rest of my work can be done through Windows. The calls come from Sipvicious and 401 which both cannot be blocked from the blacklist. I would try from my tablet but the number differs from my desktop. What can I do in order to block these calls? This causes my occupations during the night to go to waste.

[Oizocraze]

... Help?